Winding for dynamo-electric machines



March 19, 1929. P. E. FLETCHER WINDING FOR DY NAMO ELECTRIC MACHINESFiled Jan. 16, 1926 INVENTOR Paul EF/efcher WITNESSES A'TTORNEY PatentedMar. 19, 1929. r

UNITED STATESTPATENT OFFICE};

PAUL E. FLETCHER, OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR TO WESTING-HOUSE ELECTRIC & MANUFACTURING COMPANY,'A CORPORATION OF PENNSYL- VANIA.

WINDING non DYNAMO-ELECTRIC MACHINES. c

Application filed January 16, 1926. Serial No. 81,700.

My invention relates to windings for dynamo-electric machines and it hasparticular relationto armature windings employed insmall hand or lathewound arinatures.

The principal object of my invention is to provide a novel windingforslotted armatures of dynamo-electric machines, and a method of makingthe same, whereby the winding operatlons are simplified and a morecompactvarmature is obtained.

is clear that the active portion of the winding,

which is embodied in the slot, is essential for the operation of suchmotors, it is obvious that any means or method "which will simplify, andreduce the cost of, the winding operations, or whichwill decrease thesize of the winding hcadsoutsideofthe slots, will go constitute amaterial advance inthe art, Particularly, a decrease in the size of thecoil heads on both sides of the armaturewill not only render-thearmature more compact but it will also directly increase the efliciencyand the capacity of the motor, since the shortened coils will give asmalls armature resistance, with a resultant decrease of the armaturecopper losses.

According to my invention, a slotted arma-' 4.0 ture is so wound that aslot is skipped between successively wound coils, thus wind ng the coilssuccessively 1n every second slot and continuing so until all the slotsare fully wound. The coils are then serially connected into a closedcircuit in the geometrical order in which they follow each other uponthe peripl'ieryo'l the armature without regard to the sequence followedduring the winding operations. 4 p

In the accompanying drawings,

Fig.1'is an end elevational view of a partially wound ll-slot armaturemade in accordance with my invention, I r

Fig. 2 is a developed diagrammatic view of the armature winding and theassociated commutator illustrating the principles followed in making thewinding of the armature shown in Fig. .1,

Fig. 3 is a diagram illustrating the sequence followed in winding thecoils into the slots of the ari'nature shown in Fig. 1, and

Fig's. d and- 5 are views similar to Figs. 2 and 3, respectively,illustrating the applicatlon of my invention to a 12-slot armature.

Referring to Fig. 1, a cylindrical armature 51 of a dynamo-electricmachine is provided with eleven partially closed slots numbered inconsecutive order S, to S The type of armature here illustrated isordinarily employed in small two-pole series motors to which myinvention is principally applied, althoughthe principles thereof areapplicable to any other pole number or any other type of armatureemploying similar windings. l V

The armatures are usually wound on a lathe, eitherby machine. or byhand, a coil being wound into pairs of slots so as to provide two coil:sides per slot. Beginning, for

instance, in slot S, and choosing a coil pitch has the requisite numberof turns, being about half of the total numbcrot turns per slot.

According to the method 01" winding employed in the 'prioryart, thenext'coil would then be wound in the pair of slots immediately followingthe slot pair S,, S but ,.accordingto the improved metaod ofwindingconstituting the subject-matter of my invention, the slots immediatelyfollowing those carrycoil is wound into the next slots, in the presentcase, in the slots S and S ,The third coil is similarly wound into theslots S and S after skipping the slots S, and S immediately followingthe slots into which the second coil is wound.

This process is continued, progressing around the armature until all theslots are filled with eleven coils, C, to C,,, there being two coilsides per slot, as shownin the developed viewv of the complete Windingin Fig. 2. In this figure, the coil-sides lying in the bottoms of theslots are indicated in dotted line, while the coil-sides lying in thetopsof the slots are shown in full lines. The sequence of: the windingoperatlons appears .ing the first coilareskippcdand the second i veryclearly from Fig. 3, indicating the succession in which the individualcoils C to C are wound into the slots.

\Vhen the armature is completely wound, each coil lies in thesame slotthat it would occupy had the armature been wound according to thepractices of the prior art, that is, by progressing from slot to slotcompletely around the armature without skipping any slots. Theindividual coils are connected to the commutator in a closed circuitexactly as ifthey had been wound according to the prior art. The coilswhich follow each other geometrically around the periphery of thearmature are connected in series without regard to the sequence in whichthey were wound. Thus, the coils are connected in a closed polygon inthe sequence C,-- .C-. s a o" -f 1o "'7" G; C11 c 01, while they arewound in the sequence C C -C etc.

The connections between successively 'following coils C -C etc., leadtosuccessive commutator segments is, to It as in the prior art. Theorder in which the various coils are placed in the slots does not in anyway -change the order in which the starting and finishing leads of thecoils appear around the armature core when the armature is completelywound and no change is necessary in laying out the commutator withrespect to the coils.

The foregoing skip-slot method of winding armatures maybe employedeither in coils with one strand or a plurality of strands, and it may beemployed in windings with one or more conductors in parallel, and forany number of coil-sides per slot. The improved method of winding doesnot impose any limitation with respect to the choice oft 1e coil pitch,but on the contrary, on account of the.

more compact arrangement of the coil heads,

it possible to choose the coil pitch with a greater degree of freedomthan in the windings of the prior art.

In armatures wound according to my invention the coils are spread outmore evenly over the end faces of the armature, the part of the windingwhich is usually tightly packed around the shaft being more evenlydistributed, a part of it being in thetplace near the periphery,whichwas notwell filled in armatures wound by prior methods.

On account of the smaller extension of the winding heads, the meanlength of turn of the coils is shorter and the armature has a smallertotal resistance, resulting in reduced losses and a greater output forthe same diameter of armature. I

The improved method of windingalso results in a more uniformdistribution of the masses around the periphery, producing moreperfectly balanced armatures, a feature which is very important in thehigh-speed first coil was wound.

series motors to which this Winding is particularly adapted.

The new winding is also more compact than the prior windings,eliminating dead air pockets between the individual coils and improvingthe rate of coolingof the coils, thus wound with the skip-slot method.Coils S, I

to S of a. five-slot pitch, are wound similar tothe eleven-slot armatureshown in Figs. 1 to 3, skipping aslot between successive coils. Thewinding operation is carried on in this manner until half of the coilsare wound into the slots, in this casesix coils S to S The next coilcannot be wound in the ordinary manner by skipping one slot, since, onacount of the even number of slots, the coil would lie in the same twoslots in which the To avoid this condit1on,'and in order to make thewinding finish properly, the first coil S of the second half of thewinding iswound in the slot pair adjacent to the slot pair carrying thelast coil S of the first half of the winding. The other coils of thesecond half of the winding are then wound by the skip-slot method justas the first half of the winding, until all the slots are filled.

As seen above, the skip-slot method ot' winding is applicable toanycombination of slots and coil pitches, there being only a slightdifference depending on whether the number of slots is odd or even. Ifthe slot number is odd, a slot is skipped between each coil. If thenumber of slotsis even, a slot is skipped between each coil until halfof the coils are wound and the next coil'is wound in the next slot, theremainder of the coils being then wound like the first half.

I'claim as my invention:

1. The method of winding slotted armatures for dynamo-electric machineswhich comprises winding a coil in-one pair of slots,

similarly winding a second coil in a pair of of coils in thegslotsomitted in group of coils into the slots skipped while winding saidfirst group.

3. The method of winding slotted armatures for dynamo-electric machineswith two COll sides per slot whi'cli-coniprlses winding a coil in a pairofslots spaced by the desired coil pitch, winding a similar second coilinto a pair of slotssecond next to said first pair of slots, winding athird similar coll into a pair of slots second next to the slots of thesecond coil, and proceeding in a similar manher until one halfof thecoils are wound, and then proceeding similarly to wind the second halfof the coils into the slots skipped in winding the first half of thecoils.

l. The method of winding slotted armatures for dynamo-electric machineswhich comprises winding a coil in a pair of slots spaced from each otherby the desiredcoil pitch, skipping the slots next adjacent to the woundpair of slots and similarly winding a second coil in another pair ofslots, and continuing to wind coils while skipping the slots followingthe preceding coil until a group of coils is formed around the entirearmature, similarly winding coils into the slots skipped while windingsaid first group and then con-i necting said coils in series in theorder of their final positions around the periphery of the armature.

5. The method of winding a commutatortype armature for a dynamo-electricmachine which comprises winding a coil in a pair of slots spacediromeach other by the desired p'olepitch, skipping the slots next adjacentto the wound pair of slots and similarlywinding a second coil in anotherpair of slots, and continuing to wind coils while skipping the slotsfollowing the preceding coil until a group of coils is formed around theentire armature, similarly winding coils into the slots skipped whilewinding said first group until the armature is fully wound, seriallyconnecting said coils in a closed circuit in the order in which theyfollow geometrically around the periphery, and then connectingsuccessive commutator segments to successive points between the coilsconnected in said closed circuit. j

6. The method of winding slotted armatures for dynamo electric machineswhich consists in Winding a coil in situ in a pair of spaced slots,skipping a slot and winding a similar COll in situ in another palrofslots, and then. continuing to wlnd coils 1n a similar manneron aroundthe armature until all of the slots in the armature are occupied by twocoil sides.

7. The method of winding slotted arma- I tures for dynamo electricmachines which consists in winding a coil in situ in one pair of slots,winding a similar coil in situ'in a pair of slots second removed fromsaid one pair of slots and then continuing to wind coils, in a similarmanner, on around the armature until all of the slots have two coilsides therein. I

In testimony whereof, I have hereunto subscribed my namethis 11th day ofJanuary, 1926.

PAUL EFLE'roHER.

